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Month: July 2021

Pork-Cat Syndrome

Pork-cat syndrome is a condition in which individuals become allergic to pork following exposure and sensitivity to cats.  It almost always occurs in individuals who have or have had cats.

Typically, if one is sensitized to cat allergen, the allergic symptoms one may develop are generally triggered by exposure to the cat allergen from the air.  These allergic rhinitis (i.e., hay fever) symptoms may include itchy eyes, red eyes, watery eyes, sneezing, nasal congestion, runny nose, post-nasal drip, itchy throat, sinus pressure, and/or sinus headaches.  Cat allergen may also trigger and/or aggravate asthma symptoms in some individuals and cause coughing, wheezing, chest tightness, and/or shortness of breath.  The treatment for classic cat allergies includes avoiding exposure to cats, medications to relieve the symptoms, and/or allergy immunotherapy (i.e., allergy injections, allergy shots, allergy desensitization, allergy hyposensitization).  Medications may include oral antihistamines, oral decongestants, leukotriene antagonists, nasal corticosteroids, nasal antihistamines, nasal anticholinergics, nasal mast cell stabilizers, ocular antihistamines, and/or ocular mast cell stabilizers.  The use of oral corticosteroids, nasal decongestants, ocular corticosteroids, and ocular decongestants are discouraged due to their side effects and/or “addictive” qualities.

What is common between cat and pork allergies?

Cat-allergic individuals are also more likely to develop food allergies, particularly to meat, than that of the general population.  The most common type of food allergy related to a history of a cat allergy is that of an allergic reaction to pork.  The symptoms generally begin within an hour after the ingestion of pork.  The usual symptoms may include generalized itching (i.e., pruritus) and/or breaking out in hives (urticaria).  These symptoms can be followed by abdominal cramping, nausea, and diarrhea.  Rarely, more severe reactions such as a sudden drop in blood pressure or throat swelling, which can cause a difficulty in swallowing or breathing, or life-threatening anaphylaxis may occur.  Needless to say, allergic reactions need to be quickly identified and treated with medications in order to stop them from progressing to anaphylaxis.  As meat allergies cannot be desensitized at this time, sensitized individuals should avoid exposure to meat at all times.

The reason that some cat-sensitized individuals are susceptible to pork allergies is that some individuals are not only allergic to the cat dander, but are also allergic to a protein found in cats called albumin.  Albumin is also found in meat from pigs and other animals.  The albumins share several common amino acid sequences.  This phenomenon is termed cross species cross-reactivity.  When albumin is consumed after eating pork meat, an allergic reaction may occur in some cat-sensitive individuals (i.e., in patients that are allergic to cat albumin).

The diagnosis is suspected when a person with a history of allergies to cat also reacts to pork.  It is confirmed by the demonstration of the presence of specific antibodies to both cat and pork allergens.  This is accomplished by skin prick testing and/or laboratory tests.  Skin tests with raw pork are usually positive but with baked meat can be negative since the heat often denatures the protein.  An oral food challenge to pork may sometimes be needed to establish the diagnosis.

This condition should be distinguished from the more common allergies to mammalian meat caused by antibodies to a carbohydrate called alpha-gal.  This condition, which is known as mammalian meat allergy, usually follows a tick bite which introduces the allergen into humans.  In this condition, the symptoms usually begin several hours after ingestion of mammal meat (e.g., beef, pork, lamb, venison) as a “delayed anaphylaxis.”  The diagnosis is confirmed by the detection of specific IgE antibodies to alpha-gal in a blood test.  Some individuals with this condition will have their sensitivity reduced after several years of avoiding the ingestion of mammalian meat.

The management of pork-cat syndrome entails reducing exposure to cats as well as avoiding of pork at all times.  Some individuals will be able to tolerate well-cooked pork, as high temperatures can denature the offending protein and render it less harmful.  Most patients with this condition also need to carry self-injectable epinephrine for emergency use in case of a severe reaction after the accidental exposure to pork.

The board certified allergy doctors at Black & Kletz Allergy have 3 office locations in the Washington, Northern Virginia, and Maryland metropolitan area.  The allergy specialists at Black & Kletz Allergy treat both pediatric and adult patients.  We have offices in Washington, DC, McLean, VA (Tysons Corner, VA), and Manassas, VA.  All 3 of our offices have on-site parking and both the Washington, DC and McLean, VA offices are Metro accessible.  In addition, the McLean, VA office has a complementary shuttle that runs between our office and the Spring Hill metro station on the silver line.   For an appointment, please call our office or alternatively, you can click Request an Appointment and we will respond within 24 hours by the next business day.  The allergists at Black & Kletz Allergy have been helping patients with food allergies, hay fever, asthma, eczema, sinus disease, hives, insect sting allergies, immunological disorders, and medication allergies for over a half a century.  If you suffer from any allergy, whether unusual or not, it is our mission to improve your quality of life by reducing or preventing your unwanted and bothersome allergy symptoms.

Allergies to Pets

Do you suffer from allergy symptoms when you go near a pet? Do you suffer chronic allergy symptoms when living in the presence of a pet? If you answered yes to either of the above questions, then you may in fact have a pet allergy. The classic symptoms in someone who has a pet allergy may include sneezing, nasal congestion, runny nose, post-nasal drip, itchy nose, itchy eyes, redness of the eyes, watery eyes, itchy throat, sinus pressure, and/or sinus pain. The official medical term for these symptoms is allergic rhinitis in an individual who is allergic to pets. The same symptoms are also found in allergic individuals who are allergic to dust mites, molds, and/or pollens. Some individuals may experience wheezing, chest tightness, shortness of breath, and/or coughing when exposed to pets. These individuals are said to have pet-induced asthma. Unlike allergic rhinitis, asthma can be life-threatening and thus must be dealt with in a serious manner.

In pet-allergic individuals, the offending allergen is usually the pet dander, saliva, or urine. Depending on the pet, the allergen may be more likely to be the dander, saliva, or urine. In dogs, Can f 1 is the primary dog allergen. This major dog allergen tends to mostly be in the dander of dogs. In cats, Fel d1 is the primary cat allergen. It is primarily secreted through the sebaceous glands and is found mostly on the skin or fur. In addition, another common cat allergen by the name of Fel d 4 is produced in the salivary glands and secreted into the saliva of cats. The licking of the fur by a cat is the perfect storm for cat-allergic individuals as they are exposed to dander that is covered in cat saliva exposing the cat-allergic individual to more cat allergens. Still other pets (i.e., mice, rats) have their major allergens produced in their urine. The major allergen found in mice is known as Mus m 1. This allergen tends to be found more in the urine of mice. In these 3 examples above, it is important to note that major pet allergens can be found in various places in the animal which depends on the specific pet.

Another way that pets can contribute to one’s allergies includes it being a vector to carrying other non-pet allergens to the allergic individual. In other words, pets act as a carrier of other allergens, most notably pollen allergens. When a dog is outdoors for a prolonged period of time, pollen can fall on its fur/hair. This in turn may cause a problem for an individual with pollen allergies once they come in contact with the pollen-covered dog. It is for this reason that it is recommended to wash your pet after a prolonged exposure outdoors, particularly in the Spring or Fall, when pollen counts are the highest.

Some individuals with pet allergies may experience skin manifestations upon exposure to pets irregardless if they have associated allergic rhinitis or asthma. Some may develop eczema (i.e., atopic dermatitis) while others may develop urticaria (i.e., hives).

The diagnosis of pet allergies is usually confirmed by a board certified allergist like the ones at Black & Kletz Allergy. After an initial comprehensive history and physical examination, allergy skin testing is usually done in order to verify a true IgE-mediated allergy to the specific pet (e.g., dog, cat, rabbit, horse, mouse, rat, guinea pig, hamster, bird). Occasionally allergy blood tests may be utilized in addition to or instead of allergy skin testing.

The treatment of pet allergies usually begins with avoidance. It is always preferable to avoid the offending allergen if at all possible. It is also known that people love their pets and usually will not voluntarily part with them. Knowing this, there are a variety of treatment modalities ranging from medications to allergy shots. Medications may include oral antihistamines, oral decongestants, leukotriene antagonists, nasal corticosteroids, nasal antihistamines, nasal anticholinergics, ocular antihistamines, ocular decongestants, and ocular mast cell stabilizers. Oral and ocular corticosteroids are rarely used due to the potential side effects. Allergy shots (i.e., allergy injections, allergy desensitization, allergy immunotherapy, allergy hyposensitization) are a very effective tool to treat pet allergies. They have been used in the U.S. for more than 100 years. They can be given to both children and adults. Allergy shots are effective in 80-85% of individuals who take them. They can be given in combination with other allergens that an individual may be allergic to such as pollens, dust mites, and molds.

If you have or think you have pet allergies, the board certified allergy specialists at Black & Kletz Allergy have been diagnosing and treating patients with pet allergies for over 50 years in both children and adults. We have office locations in Washington, DC, McLean, VA (Tysons Corner, VA), and Manassas, VA. Our Washington, DC and McLean, VA offices are Metro accessible and there is a free shuttle that runs between our McLean, VA office and the Spring Hill metro station on the silver line. The allergists at Black & Kletz Allergy are extremely knowledgeable about the most current treatment options for patients with allergic rhinitis, allergic conjunctivitis, and asthma and can promptly answer any of your questions. To schedule an appointment, please call any of our offices or you may click Request an Appointment and we will respond within 24 hours by the next business day. As mentioned before, we have been servicing the greater Washington, DC area for more than 50 years and we look forward to providing you with excellent state-of-the art allergy and asthma care in a welcoming and pleasant environment.